A previously unpublished study of gap-year students indicates that privately educated teenagers are three times more likely to take a year out before university than their state-school counterparts.
Ministers announced last week that any student who had already secured a place at university for October 1998 would be exempt from tuition fees when they are introduced next year. Students who take a year off and re-apply next year, however, will have to pay.
But Professor Alan Smithers, of Brunel University, who conducted the research, said private-school pupils were much more likely to plan a year out - and to have secured a deferred university place - than those at state schools.
The research will reopen the argument about the thousands of students expected to take an informal gap year and reapply for university in 1998 who are not covered by the fees concession.
A spokeswoman for the National Union of Students said it was not fair to offer free tuition to people with deferred places, but not to those who had decided to wait for their results before applying to university. The NUS is still considering legal action to challenge the Government's decision, she said.
Lis Pritchard, project manager at Gap Activity Projects, which organises gap years abroad, said: "The concept began in the independent sector and it's more well-known there. The independent sector is disproportionately represented in people taking formal gap years and we are trying to promote it in the state sector."
She criticised ministers for basing their fees concession on those students with a deferred place. Many students had arranged a gap year months ago, but had been advised to postpone their university application until after the A-level results. Others were applying to institutions which did not offer deferred places.
She said: "We have a lot of people, often good candidates, who would benefit from a gap year but are being hammered."
The study, by Professor Smithers and Dr Pamela Robinson at the Centre for Education and Employment Studies at Brunel University, surveyed 468 sixth-formers going on to university.
Of the 92 independent-school pupils in the sample, 19.6 per cent or 18 took a year out compared with only 6. 1 per cent or 23 of the remaining 376 state-school pupils .
Professor Smithers said: "In the case of independent schools, gap years tend to be pre-planned and an aspect of that is that people arrange a deferred place. The people who went about it more casually were the state-school pupils."
The Brunel research focused on the gap-year students once they reached university. Professor Smithers and Dr Robinson found two thirds of gap-year students had difficulty adjusting to the academic side of university life, well up on the 42 per cent of non-gap-year students who had problems. However, students were better able to cope socially after their year out. Only 17 per cent reported problems, compared with nearly a quarter of those who did not take a year off.
* Universities were reassured this week that the Treasury will bear the cost of students who do not pay tuition fees. Officials said the Government would make up the shortfall from students exempt from the #163;1,000-a-year contribution towards fees.
A question remained, however, over the 53,000 students from Europe who study at British universities. Ministers are considering how they should be treated under the tuition fee regulations.